So my friend has built a pc for his friend using some spare parts and bits that i bought. The power supply just has a 20 pin connector and while the pc seems to work fine i'm not sure if it will function properly, especially if overclocked which was the plan. Can anybody confirm whether this will effect anything? The PSU is about 500w with 28a on the 12v.

Ducky Year of the Snake w/ Cherry MX Browns & Year of the Tiger PBT Keycaps | Razer Deathadder Black

I have a feeling he's going to notice intermittent issues (random restarts, blue screens, etc.) before he physically fries something. If he decides to go for it with what he's got, have him keep a close eye on vital signs.

I'll let somebody else chime in on this, though. The exact make and model of the PSU, Motherboard, CPU, and maybe the graphics card as well could help.